Reinforced concrete beam



April 28, 1953 Filed Nov.

M..G. HILPERT REINFORCED CONCRETE BEAM fgajw: @B

nventor Gttomeg Patented Apr. 28, `1953 UNITED STATES PATENT OFFICEREINFORCED CONCRETE BEAM Meier George Hi1pert,.Bethlehem, Pa.

Application November 7, 1945, Serial No. 627,211

4 Claims.

. The invention relates to composite beams, panels thereof, columns inbending, and the like and has as an object an improvement in thestructure of steel elements thereof by providing for the more economicaland ready fabrication, and assembly thereof in position for theapplication of the concrete to complete the composite structure.

It is an object of the invention to provide a method of forming seatsfor reinforcement and shear rods for full diameter bearing and which maybe embodied in a rolled or a built up steel tension member for beams,columns, panels, slabs, and the like.

It is a further object to provide a spring clip or the like for holdingof said rods in steel against steel bearing in their seats.

It is a further object to provide an improved form of a spacing chairfor holding temperature and additional reinforcement rods in properposition during concrete construction. For example, the improved form ofspacing chair may be used during the pouring of the concrete slab of acomposite member in beam or panel construction.

Further objects will appear from the following description when read inconnection with the accompanying drawings showing illustrativeembodiments of the invention and wherein- Figure 1 is a side elevation;

Fig. 2 is an end view of a plate illustrating one method of formingseats for rods;

Fig. 3 is a side elevation;

Fig. 4 is an end view of a similar method of forming seats in a beamstructure;

Figs. 5, 6, '1 and 8 are detail vertical sections Y of diierent forms ofinverted T beams combined with the reinforcement rods and concrete ofcomposite constructions;

Fig. 9 is a detail side elevation of a seat for a square rod, the rodbeing shown in section;

Fig. 10 is a detail side elevation showing a rod in section with oneform of spring clip for holding the rod to its seat;

Fig. 11 is a detail plan view of the structure of Fig. 10; v

Fig. 12 is a view similar to Fig. 10 showing aA different form of clip;

' Fig. 13 is a detail plan View of the structure Fig. 12;

' Fig. 14 is a side elevation of the clip of Figs. 12 and 13 as seenfrom the left in those figures; Fig. 15 is a detail side elevation of aform of chair;

Fig. 16 is a detail plan view of the structure of Fig. 15;

' Fig. 17 is a detail vertical section to an enlarged scale of upperportion of Fig. 8 showing a chair as of Figs. 15 and 16 supportingtemperature and upper reinforcing rods, and form work supported from oneiiange of the rod seating T member of the invention; and

Fig. 18 is a detail side elevation of the right half of a composite beamshowing several features of the enlarged detail Fig. 1'I and theconcrete slab combined therewith.

This invention relates to composite beams and panels thereof, havingconcrete or other plastic compression flanges in combination with steelwebs and the necessary steel tension flanges'and its general object isto provide a novel means for the proper transferal of the stresses dueto all beam loadings-dead, live, impact, traction, expansion, etc., asapplied to said slab or compression iiange, thence to the steel web,which being integral with'the steel bottom iiange, completes the properdistribution of stresses for whatever loadings said beams, or panelsthereof, have been designed. The application of the composite beamprinciple in engineering design has, in these United States of America,to date, been lacking in most fields of construction, and notably forhighway and railroad bridges. This could be due to concentration ofengineering research in the two separate fields, i. e. steelstructures'and concrete structures, but there are many cases where thecomposite beam principle is indicated for economy and service. Forexample, in most building construction for girder beams, ller beams,joists, special T-beam joists', and rigid frame structures; in highwaybridges fory simple beam spans, stringers, and floor beams; in railroadbridges with ballasted track for simple beam spans, stringers, and floorbeams in certain special constructions; also in rigid frame bridges itmay be applied for the horizontal and vertical legs. Many spans havebeen built with all the dead load carried by the steel beam, and thelive plus impact loads carried by the resulting composite beam, but asthe dead load moment is a large part of the total moment (about 50% fora 58 ft. beam span) such composite beam has not been designed for itsmaximum efficiency. In most cases where a concrete slab is required todistribute and carry loads to steel beams, practically all of the slabshould be used with the steel beam to form a composite beam.

One very obvious reason for this limited use of the composite beam isthe lack of a satisfactory and positive means of transferring thehorizontal shears from the concrete to the steel beam. A normal bondexists between the steel and concrete when it first sets, but corrosion,impacts, and vibrations may break this bond, a fact which has beenobserved on bridges in use. While several types of shear connectionshave been used, such as clip angles riveted to the beam flange, barsWelded to the beam iiange, and certain proprietary types, etc., nonehave been generally accepted or standardized. The angles and barsfastened to the flange` d o not satisfactorily lock; the concrete to thesteel beam vertically and' as soon as any separation occurs, theei'uciency as a composite beam is reduced. To be completelysatisfactory, the means used to transfer the hcri zontal shears shouldalso rigidly and permanently lock the concrete to the steel even thoughshrink:-` age and temperature changes occur.. and. impact. on occasionis excessive.

A decided factor aiding in the efficient and economical use oi thecomposite beam principle is; welding. En the past. tel-1. yearsthe useof. welding-has extensively cha-.need steel construe-r tion in allbranches, oi steel fabrication` except-- ing for highway and railroadbridges,1 where its, use is still negligible. By means of Welding, spe5cial sections can ce formed for special conditions, flange sectionsvaried as desired.,V and, in general any section can be. formed toutilize the, steel to its maximum strength. In this connection itis tobe noted that composite construction reduces vibration in beams andgirders^ For example, tests, show that composite. construction increasedthe4 resisting moment. o observed girders by 35 t0 510 per cent, whiletheir resistance to vibrations Was increased from 250 to 300. per cent.

Any composite building project of' size requires a` considerable numberof steel shapes, many duplicates. By constructing such shapes in thevmanner shown and described herein, T members are made by splitting Ebeams or by assembling plates and thereby substantally any size andweight of steel member may be provided for the purpose, in accordancev-'ith the needs of the Work in hand.

To provide seats in the steel member ior the shearl and reinforcing rodsto be embedded in the conc-rete slab ci a compositev member and inaccordince with the invention, Besnaped open. ings. 29 are; punched in aplate as. shown in Figure I or in the. web of an i beam as shown in Figi3 with the rounded parts 2i ci the p erforations of correct size to iitthat size of rod refniired,v theV perforations being of such depth asto, provide for metal which may be removed in serering the. parts asindicated in dash line atV 22.

Ordinary rod seats. may also be, termed to proper depth ier suchordinary reinforcing bars,

as are not needed for shear. The plate or E beam is: then severed in.any usual mannen as lray-'burningtorch, along the line. 22- thus, givingtwoduplie cate members The. spacing oi the perte-rations; 2dr and; 23.is. made at the locations in which Galc-ulations showthat rcds both forshear and ordi nary reinorcement shouldv be located ier the Work inhand.` One of the. thus provided T beams. may be used as such for atension mein-- ber ci a composite beam asV indicated at` 2li in Fig. 5.with the necessary rods olaced i. the. seats as shear rods and/o1'ordinary reinforcing rods, or if standard rolled Is are deficient indepth of web and/or bearing for shear,I such` tension member may beprovided by slitting a plate. such as shown inligure l which be weldedat. 25 toA a T beam 23, to. be combined with the. slab Qt the concrete.as at. ci.l

If greater vertical loadings are to be met onehalf of a smaller I beamsuch as shown in Fig. 3 forming an auxiliary inverted T may be welded asat 28 to an inverted T beam 29 as shown in Fig. 7 and the rods may beplaced in the seats provided by the perforations 2i) and 23 in theprojecting web of this auxiliary T.

3 shows a form of built up T `beam comprising a danger plate 3Q anda webPiate 3| having an auxiliary T seat member 32 shown as onehalf of a beamof Fig. 3 welded to the top edge or the web plate 3i as at 34, whichconstruction will; provide for any desired strength of composite beam.

The seats shown as for rounded rods at 20, Figs. 1. and 3. may hare,square portions if desired for the reception of square shear and/orreinforcing rods 35 as shown in Fig. 9.

In all cases the opening 35 to the seat is made of a. size to allow arod to drop freely into position so that it may then be pushed intoits-proper seat for full bearing and shear, as.. indicated. in Figs.. 9,1,0, and, l2..

i-nids may be, secured in their seats. by driving; a steel; wedge`between, the rod a portion; ot the opening. however., when thispractice. iS followed an undue strain is placed upon the. metal andy inthe placingV of` the concrete. with the usual tamping Q13 vibrating, theWedges are liable. to. displacementV leaving thebar without a metal-tofmetal contact withy the; beam web.. To. avoid this. contingency and tohold the par resiliently inl constant contact with its seat and. such a.manner that it. cannot become, displaced by subsequent operations theinvention provides o.. spring clip for the purpose.

as. shown in Fig., 11,l the spring clip comprises a, portion Si, to,contact, the, metal of the T beam. and, e pQrtion; 3ft-.having a roundedseat. 39. t0. bear. against the. bar with a Spring member Ml confmeeting the tivo parts. This Clin mail be con` tracted by applyingpressure; upon the portion. 4.1. or by hammering and revolving the clip.into place.

from above in Fig.. 10.

in another form of clip, a. U. member 42. is pro. vided having legs 434.1i, with rounded recesses in their extremities as. at. 4.5,.. to.engage the. rod. and. with a beam web engaging portion litl united` tothe legs by curved members.` 41 48,. This formof clip is applied to thebeam in av position shown.

in dotted lines in Fig. 12,and by a. light flow of a hammer is forced tothe, permanent,` position shown in Fig.

To prevent: displacement of said clip,Y a.. friction surfaceis providedas shown by' striking; out, portions 49. from thev metal of the plateportion 42 of the clip. It Will be seen that. the,- clipS; of, the.invention present their edges to the flow of concrete when applied..and. thus the semi-.liquid concrete,- Will readily 110W thereabout withless danger of the. formation of. air. pockets.

To support temperature bars 50 and reinforcing bars 63.a,1`o rrn cichair is. shown at 5| comprising a plate of metal recessed as at. 5.2and having wings; 53, 54. struck out from the metal thereof adjacent thebight 5,5 of the chair.. The. recesses 52 may be formed by thevstriking, out of the ears 53, 54. This chair when placed. upon. the web56 of the steel member will support. itselji in a vertical position forthe easyplacingx of. the Spacing and/or temperature. rods. to,A besupported thereby in recesses 57 in its upper,` end., and thus onlyedges. of the chair are presented to the flow of the plastic concrete.

te. Since the. anses of` the auxiliaryl 1? support the slab and verticalloadings, they may be used to support the form work necessary for theplacing of the slab, and arranged to allow of the easy removal of saidform work and reuse by sacrificing only the bolt nuts embedded in theconcrete.

In Fig. 17, there is shown a form joist 58 supported by bolts 59 fromthe anges of the superimposed auxiliary T 56 with form panels 69supported on said joist.

Fig. 18 illustrates a composite beam tension member with its bottom angeas an inverted T 6| curved upwardly at its end with a web 62 welded toboth its bottom ange and its auxiliary T, the upper edge of saidauxiliary T being formed with bar seats in accordance with theinvention.

It is well known to metal Workers that the punching out of material fromthe edge of a plate unavoidably results in a deformation of said edge,and produces a warp or camber of the plate. The method of rst punchingand then parting of the punched member of this invention entirely avoidssuch distortions, and produces duplicate members.

The invention adapts itself to the formation of composite floors, slabsor panels such as shown in Figs. 35 to 38 in my Patent 2,271,592 datedFebruary 3, 1942, and may be utilized in the building of walls, roofsand floors of buildings, and decks and oors of bridges, also in thesupporting walls and decks of many constructions, e. g. viaducts, docks,mine works, ships and the like and when composite panels are preformedto proper size they may be designed to have ample strength for handlingduring erection. The metal-to-metal contact assured by the form of theseats and the use of the spring clips insures a full transference ofstresses from the concrete through the bars by shearing strength to thesteel web of the tension member.

It is obvious that the structure of the tension member of Fig. 7 couldbe produced by rolling a special shape comprising an I beam with a pairof spaced flanges or ribs near the longitudinal center line of the web,forming the punched B-shaped openings between these supplemental flangesor ribs, and parting the special shape through the punched openings inthe manner described as applying to Figs. 3 and 4. It is also obviousthat the shape shown in Figure 6 could be made by rolling. The weldedshapes of Figures 6, 7, 8, 17 and 18 are regarded as integral shapes inthe sense of the word integral as used in the following claims.

It is also obvious that the wings of the chair of Fig. 16 could bestruck from the chair so as to lie on the face of the tension memberedge opposite to their position shown in Fig. 16.

Minor changes may be made in the physical embodiments of the invention,within the scope of the following claims, without departing from thespirit of the invention.

I claim:

1. A composite beam structure comprising, in combination: a concretecompression ange; an inverted T-metal member comprising a tension flangeand a web; an inverted and smaller continuous T-metal shape rigidlyamxed to and aligned with the edge of said web opposite said tensionflange, the free edge of the web of the T-metal shape being embedded inthe material of the concrete flange, and said T-metal shape beingprovided with openings elongated in the direction of its length formingrod seats; shear reinforcing rods seated in said rod seats and embeddedin said concrete ange; and means in said elongated openings holding saidrods in contact with one edge cf said rod seats.

2. The structure of claim l wherein said means holding said rods incontact with said rod seats comprise resilient clips located in saidelongated openings and means retaining said clips in said openings.

3. A beam structure comprising, in combination: a concrete compressionflange; an inverted T-metal member below said compression flangecomprising a tension ange and a web; a smaller continuous member havinga horizontal portion rigidly aixed to and aligned with the edge of saidweb opposite said tension flange and also having a vertical portionextending from said horizontal portion, said vertical portion beingembedded in the material of the concrete and having an upper edgeincluding openings forming seats; elongated shear preventing andreinforcing members seated in said seats and embedded in said concreteflange; and means holding said elongated members in contact with saidseats.

4. A beam structure comprising, in combination: concrete compressionilange; an inverted T-shaped metal portion comprising a lower tensionange and a vertical web; a substantially continuous member rigidly amxedto and aligned with the edge of said vertical web, said member being ofgreater width than the width of said web and being at least partiallyimbedded in said concrete flange, said member also being provided withopenings elongated in the direction of its length and forming seats;elongated shear preventing and reinforcing members seated in said seats;and compressed resilient clips seated in said elongated openings, saidclips engaging said elongated shear preventing and reinforcing membersto hold said members in contact with said seats.

MEIER GEORGE HILPERT.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 582,386 Balph et al May 11, 1897 868,065 Barnes Oct. 15, 19071,017,118 Thomas Feb. 13, 1912 1,063,003 NeeVel July 22, 1913 y1,277,876Detwiler Sept. 3, 1918 1,283,902 Hyatt et al Dec. 24, 1918 1,475,349Marks Nov. 27, 1923 1,681,932 Ellison Aug. 28, 1928 1,936,147 Young Nov.21, 1933 1,979,643 Sahlberg Nov. 6, 1934 2,016,616 Schaub Oct. 8, 19352,132,220 Powers Oct. 4, 1938 2,172,302 Tinnerrnan Sept. 5, 19392,271,592 Hilpert Feb. 3, 1942 2,340,176 Cueni Jan. 25, 1944 FOREIGNPATENTS Number Country Date 726,897 France Mar. 14, 1932 179,365Switzerland Nov. 16, 1935 526,247 Great Britain Sept. 13, 1940

